The OPTICS IS LIGHT WORK column is an outgrowth of the OSA-sponsored Optical Fabrication and Testing Workshops. It is the intentof the Workshops to communicate technology and practice in the fieldsof optical manufacture and testing to opticians and optical engineers.Those attending the Workshops generally agree that the periodicmeetings are fulfilling these goals; however, the audience that can bereached is small, perhaps 1200 people once a year. By publishing inApplied Optics a fabrication-and-test-oriented column, a far largeraudience can be reached twelve times a year.

This column is intended to be a means of timely exchange of specifictips or recipes to make the life of the optician or technician easier andmore fruitful. Reports of experiences with new products and the ap-plication of familiar products in unique ways are encouraged. Transfersof other areas of technology to the solution of optical fabrication andtesting problems would be welcomed.

Material for this column is solicited from all workers in the field ofoptics and may be submitted to either editor. Limit your note to 500words (2 double-spaced typed pages) and one illustration, just enoughto get across one specific idea or method.

Robert E. ParksOptical Sciences CenterUniversity of ArizonaTucson, Arizona 85721

Norman R. Brown L-140Lawrence Livermore LaboratoryBox 808Livermore, California 94055

Ordinary paper for position determination ofintense laser pulse

C. S. Vikram and K. Vedam

Pennsylvania State University, Materials Research Labo-ratory, University Park, Pennsylvania 16802.Received 6 July 1979.0003-6935/79/244063-01$00.50/0.C 1979 Optical Society of America.

For alignment of a ruby laser beam it is customary toplace blackened Polaroid film in the beam path and observethe location of the burn on it. However, we find that, insteadof Polaroid film, one can use any continuously printed areas(preferably black) of smooth, glossy, or semiglossy pages frommagazines, periodicals, etc. and obtain equally good results.The figure shows typical burn spots on such a printed paper(taken from American Laboratory) with various beam in-tensities from a Q-switched ruby laser. Even though ourexperience has been restricted to ruby-laser light, the methodshould obviously be applicable for the position determinationof other visible pulsed-laser beams.

This work was supported by NSF grant DMR-76-80620.

Protective coating aids polishing ofwater-soluble crystals

Daniel W. MerdesPennsylvania State University, PhysicsUniversity Park, Pennsylvania 16802.Received 5 June 1979.0003-6935/79/244063-01$00.50/0.© 1979 Optical Society of America.

Department,

When polishing small lenses of such water-soluble crys-tals as NaCl and KBr, the worker must usually deal with theoften irritating task of polishing one surface without marringthe opposite side. Whenever a lens or window is too thin toafford a good grip at the edges, I find it most helpful, afterhaving polished the first side, to spray the freshly polishedsurface with a coat of Universal 33 spray for metal blocking,available at a reasonable price from the Universal Shellac andSupply Company, Hicksville, New York. (Doubtless, similarproducts available elsewhere would serve as well.) Theproduct dries to a thin plastic coating that can then be handledwith the bare fingers without significantly affecting the surfacebeneath. After the other side of the lens has been polished,the coating on the first side is easily peeled off with the helpof cellophane tape.

This is not a perfect solution, because the surface coated inthis manner sometimes becomes very slightly fogged, but thisis barely noticeable and is of no consequence in most IR ap-plications.

15 December 1979 / Vol. 18, No. 24 / APPLIED OPTICS 4063